AB1643 ONE-MONTH HOSPITALIZATION WITH HIGH-DOSE GLUCOCORTICOID THERAPY IS ASSOCIATED WITH SARCOPENIA PROGRESSION IN PATIENTS WITH RHEUMATIC MUSCULOSKELETAL DISEASES
Authors: H. Hanaoka, J. Kikuchi, M. Akiyama, K. Hiramoto, S. Saito, Y. Kondo, Y. Kaneko
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Sarcopenia refers to a decrease in skeletal muscle mass and function. It is associated with daily life disability and a high risk of all-cause mortality. While sarcopenia is generally an age-related disease, it has been recently recognized to be prevalent in young patients with rheumatic musculoskeletal diseases (RMD). Especially, most patients with RMD with systemic organ manifestations are hospitalized to be treated with high-dose glucocorticoid (GC) leading to extremely low physical activity and prolonged bed rest for a long term. However, little is known about sarcopenia in patients with RMD who are administered high-dose GC in hospital. <h3>Objectives</h3> To clarify the incidence of sarcopenia and its risk factors in patients with RMD treated with high-dose GC therapy in more than one-month hospitalization. <h3>Methods</h3> We reviewed patients with RMD who had been hospitalized in Keio University Hospital from 2020 to 2021 and included those with skeletal mass indices (SMI) before and one-month after high-dose GC treatment available in the analysis. We divided them into two groups according to progression of sarcopenia. Sarcopenia was defined as less than 5.4 kg/m<sup>2</sup> of SMI for woman and less than 7.0 kg/m<sup>2</sup> of SMI for man according to definition of Asian Working Group for Sarcopenia. Progression of sarcopenia was defined as more than 10% decrease in SMI from baselines. We compared clinical characteristics between the two groups and conducted multivariable analysis identify independent risk factors associated with progression of sarcopenia. <h3>Results</h3> Forty-nine patients were enrolled. The mean age was 53.3 years old, and 36 patients (73.5%) were female. The most frequent disease was systemic lupus erythematosus (42.9%) followed by systemic vasculitis (18.4%) and idiopathic inflammatory myositis (14.3%). At hospital admission, 41 patients (83.7%) already met the definition of sarcopenia before high-dose GC treatment. After one-month hospitalization with high-dose GC treatment, two patients newly developed sarcopenia, and 28 (57.1%) patients were diagnosed with progression of sarcopenia. Patients in the sarcopenia progression group were male dominant (60.7 vs 90.4%, p=0.025), had a higher body weight (56.9 ± 12.9 vs 50.5 ± 7.5 kg, p=0.048), and showed higher SMI (5.5 ± 0.8 vs 5.1 ± 0.8 kg/m<sup>2</sup>, p=0.008) than those in the non-sarcopenia progression group. Age (52.8 vs 55.8 years, p=0.755), underlying diseases, and starting dose of GC (0.98 ± 0.16 vs 0.96 ± 0.19 mg/kg/day, p=0.35) were not different between the two groups. During the mean observation period of 41.2 ± 10.4 days of hospitailization, the incidence of infection was higher in the sarcopenia progression group than the non-sarcopenia progression group (28.5 vs 5.7%, p=0.042). Multivariable regression analysis revealed body weight reduction from 0 to week 1 was associated with progression of sarcopenia (odds ratio 0.22, 95% confidence interval 0.04-0.61, p=0.007) (Figure 1). Receiver operating characteristic curve identified the reduction in body weight of -1.8 kg in one week predicted sarcopenia progression after one month in-hospital high dose GC treatment. <h3>Conclusion</h3> Sarcopenia is frequent in patients with RMD, and one-month hospitalization with high-dose GC therapy worsened sarcopenia in more than half of patients. Early decrease in body weight can predict significant muscle volume loss after one month in-hospital therapy. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.